Definition

For over 20 years following Kanner's original report there was much disagreement about autism. Gradually evidence began to accumulate that suggested the role of central nervous system dysfunction in pathogenesis—for example, children with autism were prone to develop seizures of various types, exhibited delayed development of hand dominance, and showed persistent primitive reflexes. Differences in clinical features, course, and family history supported the distinctiveness of autism (for instance, apart from schizophrenia).(28,29)

By 1978 there was a substantial body of work on the validity of autism. Rutter synthesized this in his influential definition of autism, (28> which required the presence of patterns of delay and deviance in the areas of social and communication development that were not simply the result of developmental delay along with the group of unusual behaviours subsumed under the term 'insistence on sameness'. Onset before 30 months of age was required.

In the ninth revision of ICD (1977) infantile autism was included within the category 'Psychoses with onset in childhood'—continuing to perpetuate the notion that the condition might be related to schizophrenia. A somewhat different approach was taken in DSM-III, (3°) which was much influenced by the work of Rutter and where autism was placed in a new class of disorder—the pervasive developmental disorders. The latter term has been the topic of some debate, although a better term has yet to be proposed and, in any case, the term PDD has now come into general usage in both DSM and ICD. (3132>

The name chosen in DSM-III ('Infantile autism') was consistent with Kanner's original report but reflected a lack of developmental orientation; these concerns were addressed in DSM-IIIR.(33> A detailed, and more developmentally oriented, set of criteria were provided and the polythetic approach adopted (i.e. minimal numbers of criteria had to be exhibited in different areas). In contrast to Rutter(29) and DSM-III,(39 an early age of onset was not required. Unfortunately, the greater concern with developmental issues also resulted in an overinclusive diagnostic concept and it became apparent that additional work would be needed. Further impetus was given to this effort by pending changes in ICD-10.(1)

Various data were collected for both ICD-10 and DSM-IV. In addition to literature reviews and commissioned data reanalyses, an international effort was undertaken to derive criteria for autism.(34) These data suggested the following.

1. DSM-IIIR tended to overdiagnose autism.

2. There was convergence between the diagnoses of experienced clinicians and the draft ICD-10.

3. There was some basis for change in the latter system (relative to number and wording of diagnostic criteria).

4. There was support for inclusion of other conditions (for instance, Rett's syndrome, Asperger's syndrome, and childhood disintegrative disorder) within the PDD class.

As a result there was general agreement between the two official diagnostic systems in terms of the approach to diagnosis of autism and related conditions.

Autism is defined (see Table 1) on the basis of characteristic problems in three areas: social interaction, communication and play, and restricted patterns of interest.

By definition, autism must be present by the age of years. ICD-10 provides for various ways in which a diagnosis of atypical autism can be made—for example, because of failure to meet age or onset or behavioural criteria. Data on this system suggest that it has good agreement with the diagnoses of experienced clinicians, avoids the problem of the overdiagnosis of autism in the most mentally handicapped persons, and has reasonably good reliability.

Funny Wiring Autism

Funny Wiring Autism

Autism is a developmental disorder that manifests itself in early childhood and affects the functioning of the brain, primarily in the areas of social interaction and communication. Children with autism look like other children but do not play or behave like other children. They must struggle daily to cope and connect with the world around them.

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